1. Field of the Invention
This invention relates to bushing and bearing pullers, and more particularly to bushing and bearing pullers for extracting bushings and bearings from blind holes.
2. Description and Prior Art
Various types of pulling devices have been proposed for removing bushings or bearings from blind holes. One such device, shown in the U.S. Pat. No. 2,305,076 to G. M. Graham, is intended for extracting a bushing or outer bearing race from a blind hole. The device includes two jaw elements which are receivable within the center recess of the bearing race. Each jaw element has an outer tapered face terminating in a lip which is moved to engage the bottom surface of the bearing race to be extracted when the jaw elements are driven apart. The inner faces of the two jaw elements are shaped and threaded complementary to each other providing an axial opening to receive a threaded shaft of a drive member which when turned moves downwardly into the jaws driving them apart and causing them to back out of the recess and carry with them the bearing race.
The two jaw members are interconnected by pins which are received in complementary recesses formed in the jaw elements. The pins permit relative movement of the jaw members toward and away from one another to facilitate positioning of the jaw elements in the recess of the bearing race, and prevent axial misalignment of the elements as the drive member is turned into the jaw elements.
This device has limited application. Since the device relies on the stationary bushing or bearing cup to prevent rotation of the jaw elements while the drive member is being turned, this puller could not be used to extract a bearing by engaging its inner race. Also, the interconnection of the two jaw members by pins requires special machining operations to form the apertures in the edges of the jaw elements, and to form the pins and connect them to the jaw members. It would appear that the machining and assembly costs related to the use of these pins would account for a considerable portion of the overall cost for the pulling device.
In the U.S. Pat. No. 2,618,053 to M. Claps there is disclosed a bushing puller which includes two pulling members, a drive shaft and a thrust block. The pulling members have slots arranged to receive the pins carried by the thrust block to establish a connection between the thrust block and the pulling members while the drive member is turned into the thrust block to extract the bushing.
Although the machining and assembly of this bushing puller is simpler than that for the pulling tool provided by Graham, the bushing puller shown by Claps requires an additional member in the form of the thrust block. Also, the device appears to be suitable only for extracting bushings and outer bearing races from blind holes as is the device provided by Graham.